| 摘要 |
1,075,474. Extruding foamed synthetic resins. G. MISSBACH. Aug. 4, 1964 [July 27, 1963; March 23, 1964], No. 30951/64. Heading B5A. A web of foamed polystyrene or other foamed synthetic material is produced by extruding the material through a nozzle having a smoothly flared outlet passage in which the foaming process is substantially completed. A tubular web is extruded through a nozzle comprising ring sections 6, 8 surrounding a core 7, 9 the parts 8, 9 forming an outwardly flared flow passage 7a in which the material is expanded by applied heat. The extruded material is inflated into a tube 9b. The core 7, 9 is coupled by a member 10a to the extruder screw 4 so as to be movable axially therewith to vary the thickness of the extruded web. The latter may be cut into two halves by circular knives 11, 12 (Fig. 4, not shown). |
